Table 4 Regression analyses for ICU mortality including patients ≥ 65 years using a model including all variables available at baseline

Complete Case Analysis—Model including only frailty (n = 13,602)

HR^a (95%CI)

P-value

vulnerable (CFS 4)

1.15 (1.07–1.24)

0.00021

frail (CFS 5–8)

1.52 (1.43–1.62)

 < 0.0001

Complete Case Analysis—Model including SOFA as severity index (n = 12,972)

HR^a (95%CI)

P-value

Frailty

vulnerable (CFS 4)

1.1 (1.05–1.16)

0.00029

frail (CFS 5–8)

1.34 (1.25–1.44)

 < 0.0001

Severity

SOFA (one point increase)

1.14 (1.1–1.19)

 < 0.0001

Gender

male vs female

0.97 (0.89–1.06)

0.51997

Age

Age (5 years increase)

1.2 (1.15–1.25)

 < 0.0001

Multiple Imputation Analysis—Model including SOFA as severity index

HR^a (95%CI)

P-value

Frailty

vulnerable (CFS 4)

1.1 (1.04–1.17)

0.0006

frail (CFS 5–8)

1.35 (1.26–1.45)

 < 0.0001

Severity

SOFA (one point increase)

1.14 (1.1–1.19)

 < 0.0001

Gender

male vs female

0.95 (0.87–1.04)

0.27293

Age

Age (5 years increase)

1.19 (1.15–1.23)

 < 0.0001